Drilling apparatus



May 11, 1943. w. -w. PAGET DRILLING APPARATUS Filed Dec. 5, 1940 xlw ,2,2.

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Awa' m@ May 1l, 1943 w. w. PAGET 2,318,522 DRILLING APPARATUS Filed Dec. 5, A1940 s sheetssheet 2 May l1, 1943. w. w. PAGET f DRILLING APPARATUS Filed Dec. 5, 1940 .v @Sheets-Sheet 3 @MMM- Patented May l1, 1943 DRILLING APPARATUS win w. rmi, Michigan city, ma., mmm u Sullivan Machinery Company, a corporation of Massachusetts Application December 5, 1940, Serial No. 368,693 v (ci. ass-45) Claims.

further object is to provide in a rotary type drilling apparatus an electric motor for rotating the drill bit, and improved means for controlling the feeding of the drill bit and having means rei drill bit for controlling the feeding pressure. A

sponsive to the current drawn by said bit rotating motor for effecting such control. Another object is to provide with an improvediluid ac.-

tuated feeding means for a rotary drilling apparatus a valve means for controlling the now of uid relative to said feeding means and an electromagnet connected in the circuit with an electric motor for the drilling apparatus and operative for controlling said valve means. Still another object of this invention is to provide an improved electromagnetically controlled valve means responsive to the variations in load on the drill bit rotating motor for controlling automatically the feeding means; Another object is to provide an improved valve means controlled by an electromagnet that is connected in the circuit with an electric bit rotating motor and continuously urged by the magnetic force of said electromagnet during the operation of said motor in a direction to reduce the supplyA of uuid to. if moved ifar enough, .to vent fluid from the uuid actuated feeding means for the drill bit. Other objects andadvantages of the invention will, however, hereinafter more fully appear. A

In the accompanying drawings there is shown for purposes of illustration one form which the invention may assume in practice.

trative embodiment of the improved drillin apparatus.

, Fis. 3 is an enlarged cross sectional view taken l ontheline 3-3 ofFig. 1'.

Fig. 4 is an enlarged cross sectional view taken onthelinel4 ofFig. 1.

Fig. 5 is a detail view in longitudinal vertical section taken substantially on line 5 5 of Fig. 4.

, Fig. 6 is an enlarged detail sectional view taken 53 on the same plane as Fig. 3, showing the valve means.

Fig. '7 is a .view similar to that of Fig. 6, but

lshowing the valve means in a diil'erent position.

Fig; 8 is a detail sectional view taken substantially on line l-I of Fig. 3.

Fig. 9 is a detail sectional view taken substantially on line 8-9 of Fig. 3.

Fig. 10 is a detail sectional view taken substan tially on line l-i of Fig. 3.

Fig. li is a diticview showing the control of fluid relative to the iluid actuated feeding means for the drilling apparatus.

In the illustrative embodiment of the invention there is shown an improved drilling apparatus of the rotary type adapted for use 4with core or plug type bits in drilling roekor other such material. The drilling apparatus is generally similar to that disclosed in my copending application Serial No. 322,267, tiled March 5, 1940, now Patent No. 2,288,543, patented June 30, 1942. In my earlier led application I disclosel mechanism including coacting cylinder and piston elements for eiecting pressure uuid operated forward feed and retraction of a bit rotating motor, together with` manual means for bodily advancing and retracting the bit rotating motor and its pressure fluid operated means. Associated with the bit rotating motor is a valve controlled bythe torque o'f the motor for limiting the pressure at which the bit may be forced toward its work by either the pressure liluid operated means or the manually operated means. The drilling mechanism illustrated herein includes pressure fluid operated means and manually operated means similar to those shown in my earlier led application for advancing or retracting the bit rotating motor, but associated with the bit rotating motor of this `drilling mechanism is an electromagnetically operated valve having its winding connected in the motor circuit so that the operation of the valve for controlling .the feeding pressure on the bit will vary in accordance with the load on the motor, as will be shortly pointed out. l

Y Referring toy the drawings, it will be noted that the drilling mechanism as a whole comprises bit rotating means generally designated I, bit

. feeding means generally designated 2 and drill supporting and guiding means generally designated 3. all generally similar to those shown in my said copending application. y

The drill supporting and guiding means comprises a trunnion member 4 having a swivel plate 5 adapted to be clamped in the saddle mounting of a suitable support. Formed in the trunnion Piston I5.

' under pressure to the i it will be vnoted that there is provided in the con-4 trol head 88 a liquid supply chamber 88 to which member is a bore which receives a tube 8, the latter fixed at its ends within portions -1, 1' depending from a support member 8. The tube 8 provides a swivel mounting for the support member 8 so that the bit rotating and feeding means may be moved into positions at the side of the drill hole, and a plunger lock Il. guided within boresin one of the depending POrtions 1. is received in a recess |2 in the trunnion member 4 for locking the support member 8 in an upright position.

The feeding means 2 comprises a feed cylinder i8 slidably guided in a bore I4 in the support member 8 and containing a reciprocable feed Extending from the feed cylinder through packings I8 carried by a front head I1 of the feed cylinder is a tubular piston rod I8. A rear cylinder head i8 is suitably secured to the feed cylinder I8 and closes the rear end of the cylinder bore.- Movement of the feed cylinder in the bore |4 of the support member is limited by engagement. of the front and rear cylinder heads with the ends of the support member. Packings 28 on the feed piston sealingly engage the walls of the bore in the feed cylinder and are held in position by members 2| and 22 clamped on the rear end of the piston rod between a shoulder 28 and a plate 24, the latter secured to the piston rod, as by screws 28. Extending through the tube 8 and cylinder heads I1 and i8 is a tube 28 having threads 28 formed along a portion of its length. The threads 28 coact with the threads of a non-rotatable feed nut 80 carried by the support member 8. The tube 28 is xed against axial movement relative to the l feed cylinder by a split ring 82 seated in grooves .strainer 8l from a passage 82 formed in a member 88 attached, as by bolts, to the control head 88. Formed in the control head 88 in alinement with the feed screw tube 28 is a bore 88, and fixed within this bore is a ported valve bushing 88 having reciprocably mounted therein a control valve 81,` as shown in Fig. l0. The control valve is of the spool type and has a rearwardly projecting valve stem 88 which extends into a recess in a rotatable member h88. A pin 18 extends through a transverse bore in the valve stem and has its ends guided in slots 1| in the member 48 to prevent rotation of the valve. A pin 12 extends through atransverse bore in the end yof the valve stem, with its ends projecting into an annular groove 14 in the rotatable member 88 to lock-the valve stem and the rotatable member against relative axialmovement. The rotatable member 88 has a rearwardly extending portion 18 in threaded engagement with the sleeve portion of the non-rotatable member 48. The rear end of the portion 18 is rigidly secured at 18 to a tube 11 which extends centrally within the tube 48 and which is square in cross section. A control rod `18, which is also square in cross section, is telescopically arranged within the tube 28 at its rear end and is held against movement longitudinally of the tube 28 by a pin connection at 18 with a rotatable operating element 88 having an operating knob 8l. the element 88 held es to axial movement by a retaining pin 82 secured within the hub of the handle 84 and passing through an annular groove 88 in the member 88.'

It will be seen that on rotating the control rod 18 the tube 11 and the member 88 will be rotated and, due to the threaded connection between the member 88 and the stationary member 48, moved 'faxia1ly thereby effecting a movement of the valve a recess 38 in the rear cylinder head I8 for locking the feed screw tube against rotation during automatic feeding of the drill.

Secured to the forward end of the piston rod i8, as by welding, is a head member 88, and attached, as by screws, to the head member is a .control head 88. Threaded in an opening in the control head i.. alinement with the 'feed screw tube 28 is a member. having a sleeve portion fitting within the bore of the feed screw tube' 28, and secured to this sleeve portion, as by weld-- ing at 42, is a tube 48 having la sliding ilt within the tube 28 and acting as a sliding guide for the The drill bit rotating means I comprises herein a high speed electric motor 48 having a stator casing 48 provided at its front and rear ends with heads 41 and 48 respectively, the parts being held in assembled relation and attached to the control head 88 by tiebolts 88. The motor has a usual field 8| and an armature rotor 82 keyed to a shaft 88 which is lournaled in bearings supported in the motor heads. Electric energy may be conducted to the motor 48 from any convenient source 'through a connector plug 84 mounted on the control head 88 and wiring 88. secured to the forward end of the motor drive shaft 88 receives the drill bit..

Referring to the means for supplying liquid hydraulic feeding means,

liquid under' pressure is conducted throughs.

rod carrying the drill A chuck 81 81 longitudinally of the valve bushing 88.

Communicating with the rear end of the bore of the valve bushing is an'exhaust chamber 88 connected by a passage 88, asin Fig. 10,-with a.

groove 81 in the head member 88, which in turn communicates with an exhaust passage 88, shown in Fig. l. At the front end of the valve bushing isan exhaust chamber 88, and a passage 8|,

controlled by a reverse-ifow-preventing check valve 82, connects this exhaust chamberwith the exhaust passage 88. Surrounding the valve' bushing are grooves 84 and 88 and a chamber` 88,

with the liquid Supply chamber 88, as shown in Fig. 1. The groove. 88, as shown in Fig. l, is

vconnected by a passage |8| in the controlhead with a passage |82 inthe head plate 88, the latter passage communicating with the interior of the feed piston rod I8. A port |88 in the feed piston rod connects theinterior of the piston rod with the feed cylinder bore at the front side of the feed piston |8. The chamber 88, as shown in Fig. 8, is connected by a passage |88 to a chamber |88 which communicates, under the control of an electromagnetically operated valve generally designated |81, with a passage |88, as shown in Fig. 3. The passage |88 communicates with s.v4

passage |88 in thehead plate (Fig. 5) which opens into a recess ||8, the latter being connected by a tube I|| with the cylinder bore at the rear side of the feed piston I8. Formed in the outer periphery of the valve 81 are grooves |I4 and ||8 communicating with an axial chain-4 ber |I8 in the valve through radial ports I|1 'valve is a recess |29 communicating with the exhaust chamber 99, and opening through the walls of the valve into this recess are ports |2|. When the valve is in the position shown in Fig. 10,

the groove ||5 connects the grooves 94 and 95 5 through the ports 91 and 93 so thatliquid under pressure may flow from the supply chamber 93 to the forward side of the feed piston and eifect a retraction of the drill bit from the work. At

the same time, the chamber 99 isr connected 10 through ports 99 with the exhaust chamber to vent liquid from the feed cylinder bore at the rearward side of the feed piston. When the valve 91 is moved into its extreme position tothe left of that shown in Fig. 10, the supply groove l5 34 is connected through the groove I |5. ports ||3, chamber IIS, ports ||1, groovell4. and ports 99. to the chamber 99 so the liquid may flow to the feed cylinder bore at the rearward side of the feed piston and effect a forward feed of the drill bit. At this time, the groove 95 communicates directly with the exhaust chamber 35 past the end of the valve 91 to vent liquid from the feed cylinder bore at the forward side of the feed piston. When the valve is moved into a position between its two extreme positions, the chamber 99 and the groove 93 are connected to the exhaust chambers 99 and 35 respectively by way of the ports 99, the ports -|2| and chamber |23.

and past the right-hand end of the valve 91, to

vent liquid from the feed cylinder bore at both sides of the feed Piston. A

Referring to the improved-electromagnetically operated valve |91. see Fig. 3, it. v will be noted that received in stepped bdres- |24 and |29 35 formed in alinement with each other in the control head 39 and transversely thereof, is a sleeve y |29 havinga portion |21 ttlng the bore |24 and a. portion |23 ofl reduced diameter ttlng the bore |25. Received within the sleeve portion ,|21 4o sleeve are held firmly in place, as -by bolts |32.

Threaded within the inner end of the sleeve porfso tion |23 is a plug |33 having an opening for slidably receiving arod which extends axially of the bores |24 and |25. At one end of the rod |35 is a plunger-like portion or armature |39 extending through the open center of the coil sa |29 and at its outer end, and for as much -more thereof as is desirable, formed of a suitable magnetic material. A coiled spring |31 surrounds the rod |35 and' acts against the plug |33 and a shoulder |33 on the rod so as to urge-the n plunger portion continuously in a direction towardsthe cover plate |3|. Siidably fitting on v a reduced portion |49 of the rod-|35 is a valve sleeve |4| which also has a close sliding flt within a bore' |42 in the control head that opens 'into g5 the chamber |39. A coiled spring |43 surrounds the reduced portion |43 and acts against. a' shoulder |44 on the rod and the inner end of the sleeve |4| vto urge the latter continuously towards an enlarged head piece |45 fixed to the 70 end of the reduced portion in any suitable manner. Formed on the sleeve-MI is an end-seat ing valve portion |41 for engaging a seat |43 formed on the control head around the opening For ex- 45 Between the sleeve |4| and the rod portion |49 isan annularspace |59 connected at its inner end by a radial passage |9| to a chamber |32,

and the latter is connected, as shown in Fig. 9. through passages |53 and |54 to the groove 31. which communicates with the exhaust passage 33. It will be noted that when the sleeve |4| is held against the head piece |45 the annular space 59 is closed against communication with the passage |93. but when the valve portion |41 of the sleeve engages `the valve seat |43 and the rod |35 is moved further to the right, as shown in Fig. 7, the passage |99 is placed in communication with the space |53 and liquid is vented from the rear' end of the feed cylinder.

Formed in the control Ahead 39, as shown in Fig. 3, are alinedbores |59 and |51 extending transversely and at opposite sides of the control l e head. Arranged in the bore |55 is a manual control valve |53 which is adapted to control the flow of liquid 'under pressure to one side of a diaphragm |59 (Fig. 5) which controls'the actuation of a motor control switch |93. Arranged in the bore |51 is a manual control valve'|9| which controls the supply of liquid under pres-'- sure through the power shaft of the motor and rod line to the drill bit. The control valves |93 I and |9| and the motor control switchl |93 are fully described in my copending application Serial-No. 268,792, and further description of',

the same herein is herein unnecessary.

- 'I'he mode of operation of the improved drilling apparatus is as follows; The apparatus is clamped in position on a suitable support at the working face and the valve 91 is then moved into a position, by manipulating the control handle 3| of the valve, to supply liquid under pressure to the rear end of the feed cylinder and eifect forward feed ofthe drill motor. When the drill bit reaches a position to start drilling, forward feed willI be momentarily interrupted, the valve |9| will be operated to eifect a supplyof 'drilling' liquid to the drill bit, liquid will then be supplied to the diaphragm |53 to operate the motor control switch and start the motor, and then the valve 91 will again be adjustedto supply forwardv feeding fluid. Assuming that the load on the drillmotor is low, the current flowing through the motor and the coil |29 will be low and the spring |31 will hold the plunger |35 against the cover plate m (Fig. a). at this time the valve portionV |41 of the sleeve |4| is lheld from. the valve seat |43, and liquid will be supplied past the'valve 91 to the chamber 99, through the pasl sage |95, and past' the valve seat |43 to the 11e-ssage |93, where it is conducted to the passage |39 and tube leading to the rear end of the feedcylinder. 'I'he pressure at which liquid is supfplied to the rear end of the 'feed cylinder is sufficient to move the drill bit against the work, un-

der certain drilling conditions, and to overload the bit rotating motor 45. As the'load on the motor increases, the current through the coil |29 increases, and the magnetic force on the plunger |39 increases and will ultimately effect movement of the rod |35 in a direction to seat the valve portion of the sleeve |4| and shut on' the ilow of liquid to the feed cylinder. As the valve portion 1 |41 approaches its seat the now of liquid will be reduced and the'forward feed slowed down, and

when the flow of liquid is completely eut oil' the feeding pressure is immediately removed since there is no expansion of the liquid. It it is desired to feed the feed cylinder forwardly within between the chamber |39 and the passage |99. 73 its guide bore relative to the trunnioii member 4 during forward feeding of the drill bit by liquid acting on the rear pressure area of the feed piston, the operator need only turn thehand crank of the feed screw so as to advance the feed cylinder and increase the feeding pressure on the drill bit. If the hand crank is turned at such a rate that the feeding pressure on the drill bit continues to increase the load` on the bit rotating motor even after the end of the sleeve Hi engages the valve seat and cuts off the supply of liquid to the feed cylinder, then the current through the coil |29 will increase and cause the rod |35 to be moved to the right to a position as shown in Fig. '1, so that passage NB is placed in communication with the space |50 to vent liquid from the rear end of the feed cylinder and permit the feed cylinder to be moved forward relative to the feed piston. The venting function is at all times under the control of the electromagnet, the

- magnetic force of which varies with the load on vhand crank, the bit rotating motor might conceivably be overloaded or stalled, but 'such an occurrence is improbable. This automatic manual feeding operation enables the drill bit to be fed forwardly the combined distances of travel of the feed piston in the feed cylinder and the feed cylinder relative to the trunnion support without any manual readjustment of the drill motor ,or its controls.

As a result of this invention, there is provided an improved drilling apparatus having improved means for controlling the feeding pressure on the ous other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a drilling apparatus, in combination, a motor for rotating a drill bit, fluid actuated feeding means for the drill bit, valve means for controlling the flow of duid under pressure to said feeding means,.vaive means for controlling the venting of fluid from said feeding means, electromagnetic means varying'in strength within cerdrill bit. It will be noted that by means of the improved feed control means the feeding pressure is varied directly in accordance with the load on the drill motor. It will also be evident that there is provided with the drilling apparatus improved manual means and pressure fluid actuated means for subjecting the drill bit to a ytrolled valve means .that is responsive to the load on the drill motor for controlling thefeeding pressure on the drill bit. By reason of the improved feed control means there may be obtained an automatic or manual feeding ofthe m drill bit and a repositioning of the feeding elements at any time. Other uses and advantages of the improved drilling apparatus will be clearly apparent to those skilled in the art.

, While there is specifically described one fo which the invention may assumein practice, it

, will be understood that this form of the same is shown for purposes of illustraiton and that the invention may be modified and embodied in varitain predetermined limits in accordance with cer- [tain` load changes on said motor for controlling `means varying in strength in response to load changes on said motorwithin certain predetermined limits and operative toeffect closure of said valve to interrupt fluid fiow to said feeding means when the load on said 'motor reaches the higher limit, and means associated with said valve means and controlled by said electromagnetic means for venting fluid from said feeding means upon loading said motor a predetermined amount beyond the higher one of said load limits.

. 3. In a 'drilling apparatus, in combination, a motor for rotating a drill bit. fluid actuated feeding means for said motor, means associated with said fluid actuated feeding means for manually feeding said motor, a valve for controlling the flow of fluid under pressure to said fluid 'actuated feeding means, means including a valve for venting fluid from said feeding means, and electromagnetic means responsive to the load changes on said motor for controlling said rst and second mentioned valves, thereby regulating the feeding pressure on the drill bit.

4. In a drilling apparatus, in combination, a motor for rotating a drill bit, fluid actuated feeding means for said motor, means associated with said fluid actuated feeding means. for manually feeding said motor, means including an electromagnet responsive to the load changes on said motor and operative at a'predeterminedmotor load for automatically interrupting the flow of l fluid to said feeding means, and associated means actuated by said electromagnet on loading said f motor by saidv manual feeding means in excess of said predetermined motor load, for venting fluid from said feeding means.

5. In a drilling apparatus, in combination, an

A'electric motor for rotating a drill bit, uld actu- Y `ated feeding means for said motor, means for -controlling the supply of fluid to said feeding means and including means responsive to the current flowing in the -circuit for said motor, and means associated with said controlling means for venting fluid from said feeding means when the current in the motor circuit vexceeds. a predetermined value.

WIN W. PAGET. 

